Anatomy of the Heart: Key Terms and Definitions in Biology

how is the apex of the heart pointed?

down and to the left

pericardium

double walled sac that surrounds the heart

visceral pericardium (epicardium)

inner layer; closest to the heart

parietal pericardium

fibrous outer layer

serous fluid

between layers in pericardial cavity to reduce friction between the two layers

myocardium

cardiac muscle- majority of heart

what are the 4 chambers of the heart?

right atrium, right ventricle, left atrium, left ventricle

which chamber of the heart is the largest?

left ventricle; because it pumps blood to the entire body through the aorta

septum (fibrous): interatrial septum

between the atria

septum (fibrous): interventricular septum

between the ventricles (thicker)

what are the 2 large veins that carry deoxygenated blood toward the heart from the upper and lower halves of the body?

superior and inferior vena cava

which chamber do the superior and inferior vena cava empty into?

right atrium

pulmonary trunk

carries deoxygenated blood away from the right ventricle towards the lungs

what side of the heart sends blood to the lungs?

right side

why are arteries thicker than veins?

to withstand higher pressures than in veins

pulmonary veins

carry oxygenated blood from the lungs to the left atrium. (only vein that are oxygenated)

aorta

carries oxygenated blood from the left ventricle to all body tissues

what is the largest blood artery?

aorta

pulmonary circulation

from the right side of the heart to the lungs and back to the left side of the heart

systemic circulation

heart and blood vessels from the left side of the heart to the body tissues and back to the right side of the heart

portal circulation

part of systemic circulation; from aorta to GI tract through the live to the inferior vena cava

where is oxygen, carbon dioxide, and nutrition exchanged?

on the capillary level

how many valves are in the heart?

four

atrioventricular (AV) valves

open during heart relaxation and close when ventricles contract

tricuspid valve

between right atrium and right ventricle

bicuspid (mitral) valve

between left atrium and left ventricle; between chambers

semilunar valves

close during heart relaxation and open when ventricles contract

semilunar valves: pulmonary valve

heart valve between the right ventricle and the pulmonary trunk

semilunar valves: aortic valve

between left ventricle and aorta

what is the purpose of the valves?

prevent backflow

blood flow of heart: right side

contains deoxygenated blood

flow of blood on right side of the heart

1. enters through superior and inferior vena cava

2. to the right atrium

3. through the tricuspid valve

4. to the right ventricle

5. through the pulmonary valve

6. to the pulmonary artery

7. to the lungs

blood flow of heart: left side

contains oxygenated blood

flow of blood on the left side of the heart

1. from the lungs

2. to the pulmonary veins

3. to the left atrium

4. through the bicuspid (mitral) valve

5. to the left ventricle

6. through the aortic valve

7. to the aorta and to all body parts

cardiac circulation: right and left coronary arteries

branch from base of aorta; supplies heart with oxygen rich blood

right coronary artery

supplies blood to anterior side of the heart

left coronary artery

supplies blood to the posterior side of the heart

cardiac veins

drains the myocardium of blood and empties into coronary sinus on the back of the heart

sinoatrial (SA) node

located on the roof of the right atrium; "pacemaker" of the heart

atrioventricular (AV) node

at the between of atria and ventricles

bundle branches

in ventricular septum

Purkinje fibers

spread within heart muscle

systole

contraction phase of the heart

diastole

Relaxation of the heart

atrial systolic phase (1sec)

1. right and left atria contract

2. tricuspid and bicuspid valves open

3. pulmonary and aortic valves closed

ventricular systolic phase ( 3 sec)

1. right and left ventricles contract

2. pulmonary and aortic valves open

3. tricuspid and bicuspid valves closed

diastolic phase (4 sec)

1. entire heart relaxes (fillings)

2. tricupsid and bicuspid valves open

3. pulmonary and aortic valves closed

arteries

carry oxygenated blood away from the heart

arterioles

smallest branches of arteries

veins

Carry deoxygenated blood toward to the heart

venules

smallest branch of veins

capillaries

connecting vessels between arterioles and venules; where oxygen and carbon dioxide is exchanged

what do veins have?

valves to prevent backflow and larger lumens than arteries

what organs drains into the superior vena cava?

drains blood from head, arms, and chest

what organs drains into the inferior vena cava?

lower body

pulmonary trunk and arteries

sends branches to both lungs (deoxygenated)

pulmonary veins

bring blood from lungs to left atrium (oxygenated)

arterial pulse

pressure wave due to expansion and recoil of an artery

what is the most common arterial pulse?

radial pulse

blood pressure

pressure that blood exerts against inner walls of blood vessels; keeps blood circulating; highest in arteries, lower in capillaries and lowest in veins

measuring blood pressure: systolic pressure

pressure in arteries at peak ventricular contraction (top #)

measuring blood pressure: diastolic pressure

pressure when ventricles are relaxing (bottom #)

measuring blood pressure: variations

systolic: 110-140 mm Hg

diastolic: 75-80 mm Hg

lymphatic system

collection of tubes and organs that picks up excess tissue fluid (lymph) leaked from blood capillaries and returns it to bloodstream

lymph

clear to white interstitial fluid containing infection fighting WBCs, cellular debris together with bacteria and proteins

what type of system is the lymphatic system?

moves by milking action of muscles and respiration

lymph circulation: thoracic duct (left)

largest duct; drains lymph from 3/4 of body

lymph circulation: right lymphatic duct (right)

drains lymph of right 1/4 of body

where do both ducts empty?

subclavian veins

what is the functions of lymph nodes?

1. produce lymphocytes (WBCs); important for immune response

2. phagocytosis- engulf bacteria, viruses, tumor cells, and foreign materials in lymph

3. filtration of microorganisms from blood

4. between 501-700 nodes

spleen

1. filters and cleanses blood of bacteria, viruses, and other debris

2. destroys worn-out RBCs and return some breakdown products to liver

3. stores platelets and acts as blood reservoir

4. forms lymphocytes in adults

thymus

produces hormones for programming T-lymphocytes to do their protective role in defending the body from microorganisms

tonsils (lymph nodes)

traps and remove/filter bacteria entering the throat (digestive or respiratory tracts; part of immune system

peyer's patches

prevent bacteria in the intestine from penetrating deeper into the body

body defenses: surface membrane barriers

skin and mucous membrane- body's first line of denfense

body defenses: inflammatory response/fever

body's second line of defense; when blood is hotter than the skin of body

body defenses: immune system

WBC's; third line of defense

pulmonary valve

aortic valve

bicuspid (mitral) valve: image

tricuspid valve: image

inferior vena cava

superior vena cava

aorta

pulmonary artery or trunk

left pulmonary veins

ventricular septum

right pulmonary veins

right atrium

left atrium

right ventricle

left ventricle

pericardium: image

endocardium: image

myocardium: image